Research On Real-time Of Embedded Forth Operating System

From Smart Home to Automotive Electronics,from Real-time Industrial Control to Aerospace Military equipment,from Wireless Communication Products to the Internet of Things,embedded operating systems are everywhere.In order to ensure that real-time tasks can be completed(or started)within the deadline to meet the needs of key applications in specific environments,most of the external devices,their specific application environments determine that the embedded operating systems matched with them need to have a certain degree of real-time.There are two meanings of real-time:One is the real-time of interrupt response.Once the external interrupt occurs,the operating system should be able to respond to the interrupt in a short enough time and handle it accordingly.The second is the real-time of task scheduling.When the emergency task is in the ready state,it should be scheduled to run immediately.Embedded Forth Operating System based on Forth virtual machine is characterized by simplicity and efficiency,abstraction of hardware layer,reconfiguration,scalability,portability and interaction.It is mainly used in astronomy,military,aerospace,industrial automation,instrument and control,graphics,workstations and other embedded fields.In many embedded Forth operating systems at present,interrupt management is simple and non-nestable,the kernel is not preemptive,and cooperative round robin based on Forth virtual machine is widely used in multi-task scheduling.This interrupt processing method and multi-tasking scheduling method directly affect the real-time performance of the embedded Forth operating system,and limit the application range of the embedded Forth operating system in real-time requirements.Therefore,the research content of this thesis focuses on improving the real-time performance of the embedded Forth operating system.Specifically,it includes two aspects:one is to improve the real-time performance of interrupt response of the embedded Forth operating system;the other is to improve the real-time performance of task scheduling of the embedded Forth operating system.In order to achieve these objectives,the specific work done in this paper is as follows:(1)The task management mechanism of the current embedded Forth operating system has been improved to introduce more complex interrupt processing mechanisms and more complex task scheduling mechanisms.(2)In order to improve the real-time interrupt response of embedded Forth operating system,the interrupt of embedded Forth operating system can be nestable,and the embedded Forth operating system can be able to support interrupt immediate submission and interrupt delay submission.(3)In order to improve the real-time task scheduling of embedded Forth operating system,a real-time scheduling mechanism of priority preemptive and time slice rotation for embedded Forth operating system based on Forth virtual machine was implemented.(4)The real-time performance of the embedded Forth operating system was tested and the time slice rotation scheduling was verified.The experimental results demonstrate that the interrupt response time of the embedded Forth operating system reaches 60?s,and the task response time reaches 2.133ms.